Rubensohl

Continuation after opps overcall our 1NT

1NT - (2♦ natural) - 3♣ -

3♦    =    denies ST, does not deny 4 card M    ➲

3♥    =    ♦ ST + 4 card ♥ (does not deny 4 card ♠), natural continuation

3♠    =    ♦ ST + 4 card ♠ (denies 4 card ♥), natural continuation

3NT    =    ♦ ST no 4 card M, natural continuation